The present invention relates to keepers which are used to position ring seals between opposed mating surfaces.
Ring seals, often referred to as gaskets, are compressed between mating surfaces for making a gaseous or fluid-tight seal sealed joint between the opposed mating surfaces. Ring seals include simple “O rings”, and also include “C seals”, “V seals”, and “Z seals”. A C seal is circular and constructed with a radial cross section having a “C” shape. These C seals are constructed both with the open side of the C construction facing the center of the ring, and with the open side of the C seal facing away from the center of the ring. As two parallel mating surfaces are brought together with the C seal in the middle, the seal is compressed with the open side of the C cross section closing during compression. The ductile properties of the ring seal permit plastic deformation to occur without damaging the mating surface. To increase the elastic recovery of the seal, some C seals are provided with a circular elastic helical spring concentrically located within the center of the seal which alters the compression resistance and elasticity properties. Meanwhile, the V seal has a V cross section with the low point of the “V” constructed to point either inwardly or outwardly towards the center of the ring seal. Z seals are also typically circular and have a rectangular cross section. These seals typically employ offset grooves which are formed in the opposing mating surfaces which when forced together with the Z seal in the middle, compresses the seal into a “Z” cross section.
The above described seals are typically circular, and thus often referred to as “ring seals”. However, ring seals may take numerous configuration, such as rectangular. Ring seals also vary greatly in size. For example, ring seals can be extremely small, often only a few millimeters in diameter. When the ring seals are small in size, it is extremely difficult to manually position them properly between mating surfaces. This problem is particularly troublesome when trying to position numerous ring seals adjacent to one another between a single pair if mating surfaces.
To overcome this problem, ring seals are often affixed to keepers prior to being positioned between mating surfaces. A keeper is a substantially planar sheet, typically of metal, which includes one or more holes for affixing a ring seal. Each ring seal typically includes a circumferential groove formed at the ring seal's outer edge which is sized to receive the holes formed in the keeper. To position the ring seal in place and affix the ring seal to the keeper, the ring seal is typically pressed into one of the keeper's holes, which elastically deforms the keeper, until the hole's edge projects into the ring seal's circumferential groove. The holes formed in the keepers are positioned so that ring seals are properly positioned between opposed mating surfaces. To assist the keeper in maintaining proper position between mating surfaces, the keeper may include one or more bolt holes for receiving bolts which maintain the opposed mating surfaces together.
Keepers typically have substantially the same dimensions as the mating surfaces. Thus, once mating surfaces have been positioned together with the keeper between the mating surfaces, the keeper cannot be seen, or only the edge of the keeper can be seen. This is not a problem where a proper keeper and ring seal assembly are positioned between the mating surfaces. However, there are literally dozens or hundreds of different keeper configurations, each constructed with a different number of ring seals or with the ring seals positioned in different places. As a result of this multitude of different keeper constructions, it is common for persons to place an incorrect keeper and ring seal assembly between mating surfaces. For example it is common for technicians to place a two-hole keeper affixing two ring seals between a mating surface having three bores for passing gases or fluids. As a result, a fluid or gaseous-type seal is not established and the system leaks. Unfortunately, once the mating surfaces are brought together, it is often impossible to determine the source of the leak as it is impossible to determine what keeper assembly has been positioned between the mating surfaces.
Thus, it would be desirable to provide an improved keeper which can be identified visually even after it has been positioned between two mating surfaces.